This disclosure relates generally to flow sensors and flow switches for controlling fluid flow in a system. More particularly, this disclosure relates to a flow switch module having a dynamic pressure responsive member for controlling fluid pumps for the chemical treatment of potable water in a system.
This disclosure has application in conjunction with numerous fluid flow systems which employ a flow switch to generate an electrical signal to alert an operator or to automatically start the system to control the fluid flow through a conduct and in conjugation with devices to effectively control water treatment equipment to correctly alter the required water treatment chemicals.
One representative example to which the present disclosure relates is a flow switch of a type such as disclosed in U.S. Pat. No. 5,162,624. The latter flow switch employs a housing which can be molded from polyvinyl chloride, plastic material or other material and which defines a flow path between an inlet and an outlet of a housing. The fluid flow system may be employed for various fluids. The housing has an extension which receives a bonnet assembly for mounting a flow switch. The switch assembly carries a magnetic field responsive signal generator such as a reed switch. Electrical leads extend through the body portion of the bonnet assembly. A displaceable shuttle is exposed to the fluid flow. The shuttle is displaced by a calibrated flow rate so as to cause a signal generated state to change state and transmit a signal from the leads. A bypass path which diverts flow from the main flow path may be opened to control the fluid flow.
The integrity of any flow switch and the ability of a flow switch to reliably function to control flow over a significant lifetime can be compromised by integrating the flow switch into a flow passage—typically, a flow passage which has a linear unidirectional flow. An optimum regulatable flow is best realized with a long straight inlet conduit leading to an inlet for fluid exposure to the flow switch. An additional desirable feature for certain applications which require sanitation and extensive cleaning is that the flow conduits can be easily accessed for cleaning purposes.